0.006” is a large variation on a head surface, depending on the angle and location of the deviation. As discussed in this thread, the likely root cause is the head surface itself and the gasket revisions are the first round of fixes to try out. Many will scoff at Ford, but there is/was a viable possibility the newest gasket could fix the problem. The main issue is whether the head surface deviation(s) is consistent in location or size. or random. If random sizes and locations are the norm, then nothing but a resurfaced or new head will fix it.So my cousins car had the head gasket failure, and they determined the head was off by 6/1000s of an inch. What is this is the root cause, and not the gasket itself?